17-Hydroxybrevianamide N and Its N1-Methyl Derivative, Quinazolinones from a Soft-Coral-Derived Aspergillus sp. Fungus: 13S Enantiomers as the True Natural Products
17-Hydroxybrevianamide N and Its N1-Methyl Derivative, Quinazolinones from a Soft-Coral-Derived Aspergillus sp. Fungus: 13S Enantiomers as the True Natural Products
复制标题
17-Hydroxybrevianamide N 及其 N1-甲基衍生物，来自软珊瑚曲霉属的喹唑啉酮类化合物。
DOI：
10.1021/acs.jnatprod.1c00098
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发表时间：
2021-03-25
影响因子：
5.1
通讯作者：
Shao, Chang-Lun
中科院分区：
文献类型：
--
作者：
Xu, Wei-Feng;Chao, Rong;Shao, Chang-Lun
在MS/MS分子网络技术和HPLC-UV技术的指导下，从软珊瑚来源的曲霉菌中分离得到两个新的生物碱外消旋体：（+/-）-17-羟基灯盏花素酰胺N（1）和（+/-）-N1-甲基-17-羟基灯盏花素酰胺N（2）。进一步监测并从新鲜制备的EtOAc提取物中获得真正的天然产物（+）-1和（+）-2，而（-）-1和（-）-2是提取和纯化过程中产生的人工产物。同时，根据光谱分析、电子捕获度计算和X射线衍射数据，确定了（+）-13S-1，（-）-13R-1，（+）-13S-2和（-）-13R-2的结构，包括绝对构型。有趣的是，碱性溶液促进（+）-1和（-）-1的外消旋化，而酸性溶液抑制转化。目前的研究关注的是真正的天然产物及其人工制品，为天然产物的分离和鉴定提供了重要的见解。
Under the guidance of MS/MS-based molecular networking and HPLC-UV, two new alkaloid racemates, (+/-)-17-hydroxybrevianamide N (1) and (+/-)-N1-m e thyl-17-hydroxybrevianamide N (2), featuring a rare o-hydroxyphenylalanine residue and an imide subunit, were isolated from a soft-coral-derived Aspergillus sp. fungus. The true natural products (+)-1 and (+)-2 were further monitored and obtained from the freshly prepared EtOAc extracts, while (-)-1 and (-)-2 are artifacts generated during extraction and purification processes. Simultaneously, the structures including absolute configurations of (+)-13S-1, (-)-13R-1, (+)-13S-2, and (-)-13R-2 were elucidated on the basis of comprehensive spectroscopic analysis, ECD calculations, and X-ray diffraction data. Interestingly, basic solution promotes the racemization of (+)-1 and (-)-1, whereas acidic solution suppresses the transformation. The current research was concerned with the true natural products and their artifacts, providing critical insight into the isolation and identification of natural products.